With the progress, the jobs to be carried out by humanity are becoming increasingly sedentary, a great deal of the working day taking place in a seated position, which is not exactly the most ergonomic posture for the human constitution.
Thus, the great majority of jobs at present are carried out in a seated position, even more so in the more developed countries, in which the hard nature of manual work has being progressively eliminated and more automated jobs are taking its place that need no physical effort to perform them.
Thus, it is known that sedentary postures are increasing enormously in developed societies, and the problems that these imply for the persons concerned are increasing in parallel with this.
Modern studies on ergonomics have demonstrated the need to equip with footrests those places where people normally work in a sedentary position for more or less prolonged periods of time.
The modern science of ergonomics dedicates a great deal of time to the study of this matter and, as a result of the work carried out, standards have already been published in this respect, that include prescriptions on the minimum performances with which the footrest has to comply.
On the other hand, conventional footrests existing on the market are static devices; although they comply with the necessary regulations on height and the angle of inclination of the platform for supporting the feet to adapt to the characteristics of each user, they do not have any movement of their own; they condemn the lower limbs to anti-natural immobility, immobility which in a short time is translated into discomfort for the person and, in the long term, to problems regarding circulation of the blood and others.
French Patent Application 2644994 describes a dynamic sitting active device with a movable footrest designed to move some parts of the body of a user such as, the lower extremities, pelvis, gluteal muscles, dorsal muscles and vertebral column by means of the displacement of the lower extremities of a user seated on a tilting seat.